Subperiosteal Implants, a brief history of successes

Gathered and summarized by Gilles Poitras

Through the history of the subperiosteal implants, from the beginnings or the early generation of the 40’s to 70’s, the evolutions of the second generation of the 80’s and 90’s, to the refinements of today’s technologically advanced CAD-CAM generation with better surgical techniques and osseointegration; there were these goals: finding solutions for patients wanting teeth on edentulous maxillaries (remember, they were introduced many years before Brånemark presented the idea of osseointegration and a two-stage threaded titanium root-form implant in 1978), 13 years after he inserted the first one in 1965 and to consistently improve on the design and impression techniques to better fit the bone, on materials to reach osseointegration and on surgical techniques to make sure one does not compromise all the above improvements when placing subperiosteal implants.

Factors which play a role in the success of these implants

“…endosseous implants are not appropriate for all patients in need of implants. There are many factors which play a role in the success of these implants. Well-designed subperiosteal implants have been reported to function successfully for many years. Among the relevant factors contributing to the success of this method are implant design, atraumatic surgery, understanding of the involved anatomic structures, accurate impression techniques, and appropriate occlusal adaptations of the final prosthesis ”.³

³. Mapkar MA, Syed R. Revisiting the maxillary subperiosteal implant prosthesis: A case study. Journal of Dental Implants, 2015

Up to the late 90’s, subperiosteal implants were made of a poured metal. Coatings have been added to cause osseointegration. Nowadays, with the advanced in CAD-CAM technologies, we fabricate subperiosteal implants from a CT-Scan impression instead of an impression taken directly on the patient’s jaw bone with soft polyether impression material, giving them enhanced accuracy and removing the need of a first surgery. Another benefit of technologies is the capability to mill subperiosteal implants from blocks of titanium allow, more precisely Ti-6Al-4V, the same allow commonly used for the root form implants.

We now officially have osseointegration of subperiosteal implants as stated in the study published in 2016 by D.J. Cohen et al : Novel Osteogenic Ti-6Al-4V Device for restoration of dental function in patients with large bone deficiencies: Design, Development and Implementation : ” … patient-specific constructs designed to support dental implants … were implanted on edentulous mandibular bone. 3 and 8 months post-operative images showed new bone formation and osseointegration of the device and indicated stability of the dental implants. ”

Failures were largely caused by errors in patient evaluation, design of the implants, or operative technique.²

². Linkow LI, Cherchève R. Theories and techniques of oral implantology (book), 1970

N.B. Subperiosteal implants were placed both on maxillaries and mandibles. Most Failures occurred on maxillaries as observed by Dr. Linkow. In 1973, he stated: “A subperiosteal implant should only be done on a severely resorbed mandible where all the alveolar bone has resorbed down to dense basal bone because a subperiosteal implant merely sits on the bone. ”

Up to then, subperiosteal implants merely sat on bone and there was no official case report of osseointegration.